Pressure relief check valve



Jan. 27, 1942. A. T. NEWELL PRESSURE RELIEF CHECK VALVE Filed Feb. 4, 1941 INVENTOR ORNEY pointed out more particularly in the claims ap- 45 PatentedgJan. 27,1942 i A a i i UNITED STATES OFFICE Arthur '1'. Newell, Huntington, s 1., .assignor to Kenyon Instrument 00., Inc., Huntington Station, N. Y,, a corporation of New York Application February, 4, 1941, Serial No. 377,315

2 Claims. (01. 2775-61) This invention relates to check-valves and Fig. 3 is a-transverse section taken on the line more particularly to check-valves-having pres- 3.3 of Fig. 2. r sure-relief characteristics. 7 In the following description and in the claims The invention is applicable to fuel tank vent certain specific terms are used for convenience systems for military and naval aircraft and parin referring to various details of the invention. ticularly for aircraft which are subjected to ese terms, however, are o be given aspbroad catapulting where the fuel surge resulting from aninterpretation as the state of the art will per,- the; catapulting tends to cause a loss of fuel mit. i through the vent system. Also, aircraft may fly, Referring to the drawing more in detail, the or may even-be parked on the ground, in such invention is shown as applied to a valve comprisposition as to cause fuel to tend to flow out of ing a housing having formed therein a D esth fuel tank v t lin i sure chamber II, a vent chamber I2 and a pres- In the aboveinstancesthe check-valve in the u e lief-chamb r The P ssu e Chamber fuel tank vent line automatically closes, thereby .H m y be os by ead 5 v n a bore l6: sealing the tank vent. Any subsequent expanthreaded for attachment to the V p pe of a sion of the fuel or vaporization thereof while the ue tank the like. The head l5 y be secheck valve is'closed tends to cause excessive Cured 0 the housing It by suitablemeans, suc strains in the gasoline tank and piping system. as screws l and may be sealed by a gasket 18.

The invention is also applicable to the fuel The ventchan ber I2 comprises a bore comvent systems of aircraft tanks which are subject mumcating with the pressure chamber II to carbon dioxide purging. During this operathrough a po 20 fo d by aveireular fl e tion the check-valve may close due to the initial 2!. The flange 2 is milled o provi e a valve surge of the carbon dioxide into the gasoline seat 22. Which is inclined to the vertical by a tank, thereby preventing the proper purging opsmall angle, such o xample. 15, so that eratjon from taking place. h p h the valve is normally held in open position by It is an object of the present invention to progravity s nd atedvide a novel and improved check valve having A Valve pp 24 p d to seat on the pressure relief characteristics such that exces- Valve Seat The fl p is own as attached sive pressures are prevented from building up o a 111g Which is pivoted y 8 Pin 21 to an even when the check valve is clgsed, ear 28 formed on the housing "I and is arranged Another object is to provide a novel'and im o a theivalve is .f to swing om open to proved check valve which automatically closes in closed position- T 111g 26 is p ov ded With'an responseto areverse surge of fluid and which re-' Which is adapted to engage the housingopens when a predetermined pressure has been In to limit the movement Of the valve flapper.

built up. V r The valve flapper 24 is shown as comprising a Another object is to provide a valve of the e a disc d by a suitable valve material above type having novel and improved details 3|.s11eh, for p as a sy e c rubber comof construction and features of operation. Position- Various other objects and advantages will be The arrangement is Such that the Valve fl pper apparent as the nature f the invention is more 40 24 normally hangs vertical y, thereby leaving the fully disclosed. v port 20 open to constitute, for example, a fuel Although the novel f tu Which are tank vent. However, a surge of fluid from right to left causes the valve flapper 24 to seat against the valve seat 22, thereby closing the vent and preventing the escape of fluid.

For pressure relief purposes, when the check lieved to be characteristic of this invention are pended hereto, the invention itself may be better understood by referring to the following descripvalve is closed in the manner above menti n tion, taken in connection with theaccompanymg a spring loaded relief valve 40 is providgd i drawmg. in which a Specific embodhnent thereof the pressure relief chamber II. The pressure has been set forth for purposes of illustration. relief chamber |4 constitutes a bore which is II} the draW parallel to the bore forming the vent chamber Fi 1 1s a fron e va i n f a v v m y- I2 and communicates with the pressure chamber ing the present invention; ll through a port 4|. The pressure relief valve Fig. 2 is a longitudinal section taken on the 40 comprises a valve member formed by a disc line 22 of Fig. 1; and 42 of metal having a facing 43 similar to the facing 31 of the valve flapper 24. A guide member 44 is secured to the disc 42 and extends through the port 4|. The valve 40 is also provided with a pin 46 which constitutes a stop to limit the opening movement of the valve.

The valve 40 is normally held closed by means of a spring 50, which is seated against the valve disc 42 over the pin 46 and bears against a follower 5| which is threaded in a threaded portion 52 of the bore constituting the pressure relief chamber H. The follower 5| is provided with a pin 53 which secures the spring 50 in position. The relief pressure may be adjusted by suitable adjustment of the follower 5| in the threaded portion 52 of the pressure relief chamber.

In order to limit the opening movement of the I valve 40, a stop member is provided comprising a pin 55 which extends through a bore in the follower 5| and is adapted to engage the end of the pin 46 for the above purpose. The pin 55 may be longitudinally adjusted by suitable means and in the embodiment shown is carried by a threaded cap 56 which closes the chamber 14 and may be locked in adjusted position by a lock wire 51.

- A port 60 is provided in the wall 6| separating the vent chamber I2 from the pressure relief chamber l4. This port 60 remains open to provide a permanent vent path through the port M, the chamber l4, the port 60 and the chamber [2 when the valve 40 is open. The chamber I2 is permanently open to the atmosphere as at 62 and may beconnected to a vent pipe or the like, as desired.

In theoperation of this valve the valve flapper 24 is normally open and the valve 40 is normally closed, thereby providing a vent from the pressure chamber ll through the vent chamber l2 to the atmosphere. In response to a surge of fluid from right to left caused by catapulting or by tilting of aircraft in which it is installed or from any other cause, the valve flapper 24 is caused to seat, as indicated, thereby preventing the escape of fluid. However, when the valve flapper 24 is closed, any excess pressure which may be built up in the chamber ll beyond the pressure at which the pressure relief valve 40 is set to open, causes said valve to open against the force of the spring 50, thereby establishing direct communication through the pressure relief chamber l4 and the port 60 to the vent chamber l2 and thence to the atmosphere. The pressure relief valve accordingly operates as a by-pass for the check valve and prevents any excess pressure from being built up when the check valve itself is closed. 7

While the above described assembly is particularly adapted for use in the ventlines of ber adapted to be connected to said vent pipe and a pair of adjacent horizontal passages extending from said pressure chamber, one of said passages being open to the atmosphere to form a vent, a port connecting the end of said last passage to said pressure chamber, an inclined valve seaton said port, a gravity biased flapper valve pivoted in said pressure chamber and normally hanging vertically downwardly therein to maintain a continuous vent passage and being adapted to swing against said valve seat for closing said vent passage in response to reverse flow of fluid or when said housing is in. an inclined position, a permanently open port between said horizontal passages, a port connecting the end of the other of said passages to said pressure chamber, a spring loaded pressure relief valve in said'last port, said relief valve being normally closed and being adapted to open in responseto a high pressure in said pressure chamber to establish connection through said permanently open port to said vent passage, and

ject comprising a housing havinga pressure chamber adapted to be connected to said vent pipe and a pair of adjacent horizontal passages extending from said pressure chamber, one of said passages being open to the atmosphere to form a vent, a port connecting the end of said last passage to said pressure chamber, a valve seat on said port, a pivoted flapper valve so arranged as to be normally held in open position by gravity and adapted to swing against said valve seat for closing-said vent passage, a permanently open port between said horizontal passages, a port connecting the end of the second passage to said pressure chamber, a spring loaded pressure relief valve in said lastport, said relief valve being normally closed and being adapted to open'in response to a'high pressure in said pressure chamber to establish connection through said permanently open port to said vent passage, and valve adjusting means threaded into the other end of said second passage and closing the same.

- ARTHUR T. NEWELL. 

